Lewistown, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

775
FXUS65 KTFX 070906
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
306 AM MDT Sat Jun 7 2025

.KEY MESSAGES...

 - Breezy today across the plains, especially in Hill and Blaine
   Counties.
 - Turning warm again early next week, with 90s likely on Monday.
 - Cooler and potentially stormy weather conditions return for
   the middle of next week.

&&

.DISCUSSION...

 - Meteorological Overview:

A cold front will push across the Plains of North Central Montana
this morning, which will usher in a brief cooldown along with a
few isolated rain showers to the area this morning. Behind this
cold front, a quickly moving high pressure system will follow,
which will shut off rain shower activity along with producing some
gusty westerly winds for parts of the area, particularly in and
around Hill and Blaine Counties. As this high pressure slides
eastward, southwesterly flow at the surface and mid levels will
advect noticeably warmer air into the area for Sunday and Monday,
resulting in a very warm day Monday with many lower elevation
locations seeing highs reach the upper 80s and lower 90s. This
heat will not last long, however, as a weak surface low pressure
system and cold front will push through late Monday or early
Tuesday, bringing cooler surface temperatures in its wake. A
second, stronger system will likely develop over Eastern
Washington and Oregon, which will help funnel moisture into the
area, kicking off scattered to widespread showers and
thunderstorms, a few of which could be on the stronger side if
sufficient shear (change in wind speed and direction with height)
develops to help storms become a bit more organized. An unsettled
pattern looks to persist through the remainder of the week as
southwesterly flow develops over the area, allowing Pacific
moisture to work into the area.

 - Forecast Confidence & Scenarios:

Temperatures on Monday: Confidence in very warm temperatures on
Monday is fairly high at this time, though just how warm it gets
is subject to some uncertainty. Looking at the big picture first,
models are in very good agreement that a strong upper level ridge
will be in place across the area, which will set the stage for a
very warm day across the area. Where the uncertainty comes into
play will be the arrival of a cold front, at this time expected
late Monday or early Tuesday. There are a few models that bring
this front in a bit earlier, which would keep temperatures from
reaching the current forecast. With that said, here are the
probabilities for reaching 90 degrees in select locations across
the area on Monday:
Helena: 70%
Great Falls: 70%
Cut Bank: 80%
Havre: 90%
Lewistown, Bozeman, Dillon: <5%
Ludwig

&&

.AVIATION...
07/06Z TAF Period

The primary concern this TAF period will be for a cold front pushing
southward from Canada through the day Saturday. A wind shift to a
more northerly or northwesterly direction will follow the front,
with at least a low-end opportunity for showers Saturday
afternoon, mostly north of I-90. Instances of sub-VFR ceilings are
expected in northerly upslope areas Saturday morning. -AM

Refer to weather.gov/zlc for more detailed regional aviation
weather and hazard information.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  68  46  77  49 /  20  10   0   0
CTB  67  41  77  46 /  10   0   0   0
HLN  78  49  81  52 /  10  10   0   0
BZN  79  46  77  45 /  10  10   0   0
WYS  73  39  73  34 /  10  10   0   0
DLN  78  46  78  47 /  10   0   0   0
HVR  69  43  77  45 /  10   0   0   0
LWT  65  44  69  45 /  30  10   0   0

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$
http://www.weather.gov/greatfalls